2551666 has 32 divisors (see below), whose sum is σ = 4572288. Its totient is φ = 1056000.

The previous prime is 2551657. The next prime is 2551687. The reversal of 2551666 is 6661552.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10041 + ... + 10291.

It is an arithmetic number, because the mean of its divisors is an integer number (142884).

2^2551666 is an apocalyptic number.

2551666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

2551666 is a deficient number, since it is larger than the sum of its proper divisors (2020622).

2551666 is a wasteful number, since it uses less digits than its factorization.

2551666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306.

The product of its digits is 10800, while the sum is 31.

The square root of 2551666 is about 1597.3935019274. The cubic root of 2551666 is about 136.6494670668.

The spelling of 2551666 in words is "two million, five hundred fifty-one thousand, six hundred sixty-six".